1985 年 1985 巻 353 号 p. 139-147
Diffusion of exhaust gas from vehicles is a complex phenomenon subject to the influences of traffic flow, meteorological condition and so on. In this report, the diffusion characteristics of gaseous substance by various types of road structure were investigated by using the following experimental methods—the diffusion experiment by tracer gas, the concentration measurement of exhaust gas from vehicles around the road and the model experiment in the diffusion wind tunnel. As the result of experiments, it was found that the diffusion parameter near the ground at the roadside area was approximately three times as much as that used conventionally at present. Approach of estimation method was performed, referring to comparison of the calculation results of concentration with experimental results.